It's just one of those things that's up there with cleaning windows on my list. No matter how much I work at it there's always a bit of something left in a little nook or cranny. I grated a cup of Fontina with it over the weekend and scrubbed and scrubbed, gave up and ran it through the dishwasher and it's still not completely Fontina-free!

I have a nylon bristle scrub brush and don't have any problem - no matter how soft the cheese.

First - I run hot tap water over it until the metal gets hot (that softens the cheese) ... then scrub the inside. Then, I scub the outside going across the graters from side to side (not up-down like I would if I was grating something). Then, I give it one last internal scrubbing. It doesn't matter which direction you scrub on the inside since it's not a sharp grating surface.

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"It ain't what you don't know that gets you in trouble. It's what you know for sure that just ain't so." - Mark Twain

I'm firmly in the hot water/toothbrush camp. Old toothbrushes never die, they get bleached and become cleaning implements. Around the faucets and drain with CLR. Those little odd places that gather food on your food processor, grater, etc. Now that we use electric toothbrushes, I just go to the dollar store and buy them for so little it is ridiculous. But cheese's worst enemy is very hot water. Having no children, I've always had my water heater set very high, and even have been known to be able to fix instant coffee, cocoa, and tea with faucet water when the electricity goes out (assuming gas hot water, electric stove, which has been a combo for much of my life).

I spray it with cooking spray (Pam) before using - be sure to spray the inside too. After grating I put soap in the sink and run the grater under hot water, wiping occasionally. After the water in the sink is high enough, I let it soak for an hour or so. Any residue left will usually come clean fairly easily with a light scrubbing. If not, it goes in the dishwasher. I love Fontina, but its texture makes it one of the problem cheeses for grater residue.